Dragline construction and associated excavation equipment



F. l. STEWART Sept. 9, 1958 DRAGLINE CONSTRUCTION AND ASSOCIATED EXCAVATION EQUIPMENT Filed June 28, 1956 5 Sheets-Sheet 1 IN V EN TOR.

Felix 1. Stewart F. STEWART Sept. 9, 1958 DRAGLINE CONSTRUCTION AND ASSOCIATED EXCAVATION EQUIPMENT 5 Sheets-Sheet 2 Filed June 28, 1956 w R m .0 m a A L 8 I 5 .X Q h a J .F m

Sept. 9, 1958 F. l. STEWART 2,351,176

DRAGLINE CONSTRUCTION AND ASSOCIATED EXCAVATION EQUIPMENT Filed June 28, 1956 5 Shets-Sheet 5 mm mm mm an a C a w: mm g Felix J. Stewart IN V EN TOR. By wad-52 (Fwy FM Sept; 9, 1958 F. l. STEWART 7 A DRAGLINE CONSTRUCTION AND ASSOCIATED EXCAVATION EQUIPMENT Filed June 28, 1956 5 Sheets-Sheet 4 Felix 1. Stewart INVEN TOR.

BY Mm an Wavy Em Sept. 9, 1958 F. I. STEWART 2,851,175 DRAGLINE CONSTRUCTION AND ASSOCIATED EXCAVATION EQUIPMENT- Filed June 28, 1956 1 5 Sheets-Sheet 5 m 2 Felix 1.5fewarl INVENTOR.

\ W F Y Mm 2 I I WWW 3m DRAGLINE CONSTRUCTION AND ASSOCIATED EXCAVATION EQUIPMENT Felix I. Stewart, Huntsville, Ala.

Application June 28, 1956, Serial No. 594,523

8 Claims. (Cl. 214102) This invention generally relates to apparatus for handling bulk material, and more particularly to apparatus for handling earth or similar material which incorporates a dragline construction together with means for handling the material after it has been initially picked up by the dragline construction.

In applicants present invention, a novel dragline construction has been provided which incorporates amovable bucket mounted on a trackway on a universally adjustable boom wherein the movable carrier runs in a trackway having a downwardly curved portion for movement of the carrier during its digging operation only so that the digging carrier will be positively guided.

My invention further incorporates a movable carrier having a removable bucket mounted thereon which is disengaged from the carrier at its inner extremity of movement wherein a turntable is provided to permit the loaded bucket to be picked up by a material-carrying trolley cable and carrier arrangement in the form of a pickup trolley which also includes associated mechanism for releasing an unloaded bucket so that the dragline is substantially continuously operated with all mechanisms being controlled by a single operator.

My invention also includes the aspect of providing a movable digging carrier with a removable bucket together with a device for automatically removing the bucket from the carrier, positioning the bucket in proper relationship for a pickup trolley, providing means for releasing an unloaded bucket from the pickup trolley and permitting engagement of the pickup trolley with the loaded bucket, after which the unloaded bucket may be associated with the digging carrier for a repeat operation, thereby providing a complete digging and handling operation which may be set up in various circumstances so that materials may be excavated from substantially inaccessible positions with a minimum of effort and with a minimum of expensive machinery since the entire apparatus may be employed with a relatively small output of horsepower and relatively small expenditure for equipment inasmuch as the operation and equipment incorporates relatively inexpensive materials which are readily obtainable with such materials being associated in a manner for providing an eflicient material handling device.

Other objects of the present invention will reside in its extreme simplicity of construction, its adaptation for many uses, efficiency of operation, its wide latitude of arrangements and its relatively inexpensive manufacturing and operation cost.

These, together with other objects and advantages which will become subsequently apparent, reside in the details of construction and operation as more fully hereinafter described and claimed, reference being had to the accompanying drawings forming a part hereof, wherein like numerals refer to like parts throughout, and in which:

Figure 1 is a plan view illustrating the essence of the present invention including the elongated boom and ates Patent() "ice trackway thereon with the movable carrier, together with the turntable construction and the associated elements of the trolley pickup arrangement;

Figure 2 is an enlarged view of the trackway extension and turntable illustrating the trackway extension in alignment with the trackway on the boom to show the differences from Figure l which illustrates the trackway in perpendicular relation thereto for picking up of a loaded bucket by a trolley pickup;

Figure 3 is a longitudinal, vertical sectional view taken substantially upon a plane passing along section line 3-3 of Figure 1 illustrating the specific structural details of the device;

Figure 4- is a transverse, vertical sectional view taken substantially upon a plane passing along section line 44 of Figure 3 illustrating the details of the trackway and carrier with the removable bucket positioned there- Figure 5 is a detail sectional view taken substantially upon a plane passing along section line 5-5 of Figure 1 illustrating the relationship of an unloaded bucket and a loaded bucket as the pickup trolley is discharging the unloaded bucket and picking up the loaded bucket;

Figure 6 is a detail sectional View taken substantially upon-a plane passing along section line 66 of Figure 2 illustrating the relationship of the movable carrier and the turntable together with the mechanism for releasably holding the bucket on the carrier;

Figure 7 is a detail sectional view taken substantially upon a plane passing along section line 7-7 of Figure 6 illustrating the construction of the trackway and the pivotal connection of the boom;

Figure 8 is a detail sectional view taken substantially upon a plane passing along section line 88 of Figure 1 illustrating the construction of the switch mechanism as the outer end of the trackway;

Figure 9 is a detail sectional view illustrating the catch mechanism for holding the loaded bucket on the trackway extension on the turntable when the carrier is retracted therefrom;

Figure 10 is a detailed side view illustrating the catch mechanism for holding the buckets on the pickup trolley for permitting dumping of such buckets at a remote point without the buckets being disengaged from the pickup trolley;

Figure 11 is a detail view taken substantially upon the section line 1l-l1 of Figure 10 illustrating the relationship of the pickup T-shaped member on the pickup trolley and the removable bucket;

Figure 12 is a detailed perspective view illustrating the mechanism actuated by the loaded bucket which assures disengagement of the unloaded bucket carried by the pickup trolley before the pickup trolley reaches the loaded bucket wherein only a single bucket will be po sitioned on the turntable and extension trackway at any one time; and

Figure 13 is a schematic perspective view illustrating the .power mechanism for moving the movable carrier on the boom.

Referring now specifically to the drawings, the numeral 10 generally designates the present invention which in cludes a dragline boom construction generally designated by the numeral 12 and an associated pickup and handling mechanism generally designated by the numeral 14. In describing the boom construction, an elongated longitudinal beam 16 is provided with an upstanding bracket 18 adjacent the center thereof which is provided with a pulley block 20 at the upper end thereof together with a pulley block 22 in alignment therewith, with the pulley block 22 being mounted on a transverse member 24 at the upper end of a pair of vertical support members 26 The pulley blocks and 22 are interconnected with a mechanical advantage cable 28 which is attached to a suitable power source whereby the angular position of the beam 16 may be varied. The inner end of the beam 16 is provided with a T-shaped transverse member 30 which has a depending portion 32 at each end thereof in perpendicular relation with the lower end of the depending portions being pivotally attached to lugs 34 by pivot pins 36. The lugs 34 are supported on brackets 38 having rearward extensions 40 which are rigid with the vertical support members 26. Mounted on the brackets 38 are upwardly facing channel-shaped guides 42 which are in alignment with a longitudinal boom generally designated by the numeral 44 which includes a longitudinally extending member 46 having upstanding side walls 48 with the outer wall being higher than the inner wall. Also forming part of the boom 44 is a pair of downwardly curved channel-shaped members 50 which are integrally secured thereto with the outer wall 48 continuing downwardly and forming the outer wall or bight portion of the inwardly facing channel-shaped trackways 50. The inner edges of the trackways 50 are inturned as designated by the numeral 52 for providing a downwardly curved portion of a trackway for receiving rollers 56 on a carrier 58 wherein the rollers 56 are mounted on axles 60 extending between adjacent edges of the inturned edges 52 of the facing channel-shaped members 50.

The carrier 58 includes a rear wall 62 and an open top and front with a generally pointed front edge 64 for receiving a removable bucket 66 therein. A lug 68 is provided on the rear thereof for receiving a pair of cables 70, and a pair of cables 72 is connected adjacent the front end thereof by lugs 74. It is noted that four rollers 56 are provided on the carrier 58 and the cables 70 and 72 are employed for moving the carrier 58 inwardly and outwardly along the boom 44.

As illustrated in Figure 6, the inner end of the longitudinal trackway 46 is provided with an opening 76 in the bottom thereof having a swingable switch plate 78 mounted therein adjacent the front edge by a pivot pin 80 whereby the plate 78 will normally close the opening to permit the carrier 58 and the rollers 56 to move outwardly along the bottom of the trackway 46 and will also permit the carrier 58 to move upwardly from the trackway 50 onto the channel-shaped guides 42 on the brackets 38.

Referring now specifically to Figure 8, it will be noted that the outer end of the longitudinal trackway 46 is provided with an angulated plate 82 pivotally mounted on a transverse pivot pin 84 wherein the plate 82 forms a closure for the open upper end of the outer end of the trackway 50 as designated by the numeral 86 wherein the carrier 58 moves outwardly along the bottom of the trackway 46 and moves onto the plate 82 which moves to a horizontal position, closing the upper end of the trackway 50, whereby the carrier 58 may then move outwardly to its outermost longitudinal position. As soon as the innermost roller 56 of the carrier 58 moves beyond the plate 82, the inner end of the plate 82 acts as a counterbalance and may be provided with an enlarged portion 88 if desired for moving the plate 82 to an inclined position, as illustrated in solid lines in Figure 8, wherein the carrier 58 may then move inwardly and will proceed downwardly along the downwardly curved inwardly facing channel-shaped trackways 50, thereby moving the bucket 58 downwardly for contact with material wherein the removable bucket 66 positioned in the carrier 58 may be filled with dirt, gravel, sand or any other type of material whereby the accuracy of the digging operation of the bucket and carrier is controlled, since the device is moving in positive trackways to accurately control the position of the digging carrier thereby permitting the dragline of the present invention to dig accurate and straight-sided ditches.

For moving the carrier inwardly and outwardly along the boom 44, a pair of cable blocks or pulley blocks 90 are provided on the outer ends of a transverse member 92 on the outer end of beam 16. The cables 70 are entrained over the pulleys on the pulley blocks 90 and proceed forwardly and underlie pulleys 94 mounted exteriorly of the brackets 38 adjacent the lower ends thereof and thus rearwardly to a pair of remotely positioned drums 96 which are provided with a power shaft 98. Also mounted on the power shaft 98 is a pair of adjacent drums 100 over which the cables 72 are entrained. It is to be noted that the cables 72 approach the drums 100 from the top, while the cables 70 approach the drums 96 from the bottom whereby the speed of the cables being wound thereon will be the same as the cables being unwound therefrom, thereby keeping the cables taut at all times and providing means for positively moving the carrier 58 inwardly and outwardly along the boom 44. All of the cables proceed through suitable pulley blocks and it is noted that a pair of guide pulleys 102 is provided for the cables 72 immediately forward of the drums 100.

On the bottom of the channel-shaped guides 42 is a pair of depending lugs 104 having a pivot pin 106 extending therethrough with the pivot pin also extending through a projecting bracket or lug 108 mounted on the inner end of the boom 44 whereby the boom 44 may be adjusted about a transverse axis. The outer end of the boom or the outer ends of the inwardly facing channels forming the downwardly curved trackway are supported from the beam 16 by a substantially inverted, U-shaped supporting bracket 110 which is slidably engaged with the upper surface of the beam 16. The beam 16, the depending portions 32 and the boom 44 all swing in a vertical plane about the transverse axes 36 and 106, respectively, with the bracket 110 forming a sliding connection between the outer end of the boom 44 and the beam 16.

The bucket 66 is substantially the same shape as the (carrier and is provided with a pair of upstanding side members 112 which terminate in an inwardly extending, reversely bent portion 114 which form outwardly facing channel-shaped portions or outwardly facing U-shaped portions with the vertical bight portions thereof disposed in spaced relation. A latch member 116 is pivotally attached to the rear of the rear wall 62 of the carrier 58 and is substantially hook-shaped with a cammed free end portion 118 which, because of its particular curvature, will retain the bucket 66 in the carrier 58 when the bucket is empty, but which may be forced to release the bucket .66 in a manner described hereinafter.

Referring now specifically to Figures l-3 of the official drawings, the turntable may be pivoted from a position in alignment with the boom 44 to a position perpendicular thereto and the turntable is supported on the support members 40 which extend rearwardly from the vertical supports 26 by a vertical pivot bolt or pivot pin 120. The turntable includes a generally hollow casing designated generally by the numeral 122 and includes a bottom 124 with upstanding side members 126 with outwardly extending wing portions 128 which form extensions of the trackway and are in alignment with the bottom of the channel-shaped guides 42 when in alignment therewith for receiving the rollers 56 of the carrier 58 for supporting the same. Upwardly extending side members 130 are provided for supporting a pair of inwardly extending flanges 132 in spaced relation whereby the side members 130 form a limit for the movement of the carrier 58 since they are in the path of movement of the axles whereby the area between the flanges 132 and wings 128 form guides for movement of the carrier. It will be noted that the outwardly facing U-shaped portions 114 of the bucket 66 will be received and engage with the flanges 132 with the horizontal upper ends of the portions 114 supported thereon when the carrier 58 is retracted. Supported beneath the flanges 132 on vertical axes 134 is a pair of spring-urged catches 136 which are urged outwardly by spring members 140 but which may move inwardly to permit passage of the bucket 66 and, specifically, will be engaged in and with the U-shaped portions 114 thereof when the bucket 66 asses thereby, whereby the spring 140 will then urge the catches or latches 136 outwardly for preventing backward or rearward movement of the bucket 66 whereby the carrier 58 maybe detached from the bucket 66 by virtue of the catch 116 being released by the camming action of the upper edge of the rear wall of the bucket 66 against the hook-shaped portion of the hook or catch 116 inasmuch as the catches 136 provide a positive lock for preventing rearward movement of the loaded bucket 66.

The carrier 58 is then moved to a position within the guides 42 or on the boom 44 and the turntable may be pivoted 180 by hand or by power mechanism (not shown). Suitable limit stops may be provided, although such are not shown since it may be pivoted to any angular position for association with a pickup trolley mounted on a pair of trolley cables 142. The trolley cables 142 may be positioned on any suitable support, such as posts, trees or any other natural formation so that the pickup trolley may be moved to any desired point. On each end of the turntable 14 is a U-shaped mounting bracket 144 supporting a pulley 14-6 for the trolley cables 142, with the cable 142 being substantially tangential to a pair of rails 148 for supporting the pickup trolley generally designated by the numeral 150 and shown schematically in Figure 5. The pickup trolley 150 includes a depending T-sha-ped pickup arm 152 having the transverse portion 154 thereof received under the flanges 132 with the vertical portions thereof received between the flanges 132 and between the outwardly facing U-shaped portions 114 of the bucket 66. As the pickup trolley moves along the pickup trolley cables 142, it is transferred to the rigid support rails 14% above the fianges 132 foraccurately positioning the trolley 156 in relation to the loaded bucket 66 which is to be picked up. As the pickup trolley 15%) leaves the other end of the rails 148, it will again be supported by the trolley cable 14-2. A comealong cable (not shown) may be attached to the trolley by any'w'ell known means wherein the pickup trolley may be pulled along the trolley cables at any desired speed.

Referring now specifically to Figure 12, it is pointed out that one of the flanges 132 is provided with an elongated rod 156 mounted thereunder on a transverse pivot pin 158 with one of the rods 156 having an upwardly extending offset enlarged end portion 161) extending through an aperture 162 inthe flange 132. The other end of the rod 156 is provided with an L-shaped portion 154 extending upwardly through a corresponding opening 166 in the flange 132 wherein the offset end 160' is disposed in the path of movement of the horizontal portion of the outwardly facing Lt-shaped portions 114 of the bucket 66 substantially as illustrated in Figure 5 so that the bucket 66 will depress the end of the arm 156 having. the cam member 160 thereon and raise the L-shaped portion 164. The purposev of the arm 156 is to provide a catch for stopping an unloaded or empty bucket carried by the trolley pickup 156 before the trolley pickup 1'56 approaches the loaded bucket 66 substantially as illustrated in Figure 5. After the trolley 150 discharges an unloaded bucket 66, it proceeds along and picks up the loaded bucket 66 which has been left on the turntable and supported on the ledges 132 by the carrier 58 which has been previously retracted to an out-of-the-way position. The upper end of the L-shaped member 164 projects into the path of movement of the upper horizontal portion of the outwardly facing U-shaped portions 114 of the bucket 66, thereby positively stopping the bucket 66 before the empty bucket has come into contact with the loaded bucket and before the trolley pickup 151 approaches the loaded bucket 66.

Means is provided on the transverse portion1154 of the T-shaped pickup arm 152 on the trolleypickup-150-for retaining the bucket 66 thereon topermit thebucket 66 b to be dumped at a loading or unloading position remote from the turntable. This construction includes a mounting lug 168 at the front and rear of one edge of the transverse portion 154, together with a catch lug 170 mounted thereon by a pivot pin 172 and biased to an upstanding position by a spring-172. As the T-shaped arm 152 approaches the U-shaped portion 114 of the bucket 66, the catch 170 at the forward edge of the arm 152 will engage the lower horizontal edge of the U-shaped portion 114 and ride under the same since the spring will permit the catch 170 to pivot downwardly within the confines of the arm 154. As soon as the lug 170 passes the forward edge of the U-shaped portion 114, of the bucket 66, it will pivot upwardly and prevent movement of the U-shaped portion 114 forwardly of the arm 152. The rear lug 170 is also spring-urged with the spring 172 being sufliciently strong to withstand the force necessary to move the loaded bucket 66 off of the ledges 132 and prevent dislodgment thereof during the normal dumping operation. However, the spring 172 is of such a character that it will permit the lug 170 to swing rearwardly when the bucket 66 is positively stopped, as by catch 164, as the empty bucket approaches the center of the flanges 132. This provides a simplified construction which permits the unloaded bucket 66 to be released from the pickup arm 152 of the pickup trolley and automatically supported on the ledges 132, after which the pickup arm 152 may be moved forwardly for picking up the loaded bucket. After the loaded bucket has proceeded onto the trolley wires, the turntable 14- is again pivoted to a position in alignment with the boom 44 and the carrier 58 moved into position on the wings 128 for engagement with the empty bucket deposited thereon. It is noted that the catch 164 will maintain the empty bucket in position so that the cam surface 118 on the catch 116 on the carrier 58 will be pivoted upwardly and engage with the rear wall of the bucket 66 wherein the carrier 58 may then be moved rearwardly, and due to the absence of any resistance of rearward movement of the empty bucket 66, the empty bucket 66 will move back onto the boom 44 with the carrier 58, after which it is moved longitudinally outwardly over the switch plates 78 and 82 and then down wardly along the curved track 50. Also, it is pointed out that guide pulleys 174 are provided for guiding the trolley cables 142 downwardly and under the support mechanism for the turntable 14, which support mechanism incorporates the bracket members 40 which have the winch drums mounted thereon. out that a positive type catch may be provided for securing the carrier 58 tothe bucket 66, which positive type catch may be released as the carrier and loaded bucket enters the turntable and which may be re-actuated when the carrier 56 enters the turntable 14 for engagement with an empty bucket 66. Also, a positive latch may be provided between the arm 152 and the bucket 66 wherein the latch could be released by a trip mechanism as the unloaded bucket and trolley carrier 150 approach the turntable 14. This could be accomplished by providing a latch mechanism in engagement with the pivotal rear lug wherein the latch mechanism would be released as the unloaded bucket approached the flange 132.

In practical use of the invention, the entire mechanism may be mounted on or alongside a power device such as a tractor for supplying power to the device for lifting and lowering the boom and for moving the carrier and buckets as well as for pulling a cable for moving the trolley pickup and for turning the turntable. The vertical'supports 26 may be provided with wheels or support ing mechanism wherein additional support will be provided for the device so that the entire mechanism could be employed for digging a ditch and other purposes.

It will be appreciated that the device may be employed without the trolley arrangement whereby a dumping de- It is also pointed vice may be incorporated therein for use of the device as a loader or unloader. By reversing the orientation of the track switches, material may be gathered during outward movement of the bucket on the boom for increasing the versatility of the device. The rollers for supporting the carriage or bucket may be mounted on the inner surface thereof for engagement with outwardly facing, centrally disposed trackways, thereby eliminating any interference with the sides of a ditch being cut by the bucket.

The dragline boom of the present invention may be used sideways or upside down if desired. The buckets or other load-carrying devices such as slings, cargo nets, or the like, can run in either direction with a reversal of the track switches. The track switches may be controlled by electricity, magnets, balancing weights, as shown, springs or the like. One model of the invention moves the bucket outwardly in the curved path and inwardly along the straight path. This orientation is useful in many industrial jobs such as gravel pits, sand piles, coal yards, or in any area where it is desirable to load from a storage pile and at the same time maintain the pile in a neat condition. The various associated clamps, catches, and release mechanisms which render the device automatic may be re-orientated for a particular job and may be actuated by electricity, springs, or any suitable motivating force.

The foregoing is considered as illustrative only of the principles of the invention. Further, since numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation shown and described, and accordingly all suitable modifications and equivalents may be resorted to, falling within the scope of the invention as claimed.

What is claimed as new is as follows:

1. An apparatus for handling bulk material such as earth comprising an elongated boom, means supporting the boom for swinging movement in a vertical and hori-.

zontal plane, a longitudinal trackway disposed on said boom, said trackway including a downwardly curved portion underlying and communicating with a longitudinal portion, a carrier movably mounted on said trackway, and means for moving the carrier longitudinally of said trackway, said trackway including switch means permitting the carrier to move outwardly along the longitudinal portion and inwardly along the downwardly curved portion for scooping a load of material in the carrier, said trackway including parallel channel-shaped members, said switch means including a portion of the bottom of the inner end of each channel-shaped member forming the longitudinal portion, being pivotally mounted at its outer end and resting on a supporting ledge at its inner end, thereby communicating the inner end of the downwardly curved portion with the longitudinal portion of the trackway for permitting the carrier to move out wardly along the bottom of the channel-shaped members forming the longitudinal portion and permitting the carrier to move upwardly and inwardly from the inner end of the downwardly curved portion onto the inner end of the longitudinal portion, said switch means also including an opening in the bottom of the members forming the longitudinal portion adjacent the outer end, with the openings interconnecting the longitudinal and downwardly curved portions of the trackway, an angulated plate pivotally mounted at the inner edge of each opening and having an outer end of a size to close the opening in the longitudinal portion to permit the carrier to move longi tudinally outwardly beyond the opening, the inner end of said plate extending below the longitudinal portion of the trackway and forming a counterbalance for nor mally urging the free end of the plate upwardly whereby the upwardly extending free end of the plate will direct the carrier downwardly along the downwardly curved portion when it moves inwardly from the outermost end of the longitudinal portion.

2. An apparatus for handling bulk material such as earth comprising an elongated boom, means supporting the boom for swinging movement in a vertical and horizontal plane, a longitudinal trackway disposed on said boom, said trackway including a downwardly curved portion underlying and communicating with a longitudinal portion, a carrier movably mounted on said trackway, and means for moving the carrier longitudinally of said trackway, said trackway including switch means permitting the carrier to move outwardly along the longitudinal portion and inwardly along the downwardly curved portion for scooping a load of material in the carrier, said carrier including rollers engaging the trackway for supporting the carrier, and a removable bucket mounted therein whereby the loaded bucket may be removed and replaced by an empty bucket for permitting substantially continuous operation of the apparatus, said boom being provided with a turntable construction at the inner end thereof including an extension of said trackway, means mounting said extension for rotation from a position in alignment with the trackway to a position in perpendicular relation thereto, means on said extension for holding the loaded bucket on the carrier whereby the carrier may be moved back onto the trackway with the bucket supported on the extension, a pickup mechanism associated with said extension for removing the loaded bucket when the extension is disposed perpendicularly to the boom.

3. The combination of claim 2 wherein said pickup mechanism includes a trolley cable, a pickup trolley mounted on said trolley cable, means on said pickup trolley for releasable engagement with the bucket, and means on said extension for releasing an empty bucket from the pickup trolley, said releasing means being actuated in response to a loaded bucket being disposed on the extension whereby the pickup trolley will discharge an empty bucket on the extension only when a loaded bucket is disposed thereon whereby the loaded bucket is subsequently picked up by the trolley for assuring the positioning of a single bucket on the extension at any one time.

4. A device for handling bulk material comprising a boom having a longitudinal track and a downwardly curved track, a load carrier supported on said track, and automatic switch means for directing the carrier along the longitudinal track during movement toward the free end of the boom and along the downwardly curved track during inward movement of the carrier for picking up a load thereon whereby the device may be employed in digging a ditch, said boom being mounted for vertical swinging movement for raising and lowering the tracks and carrier whereby the elevation of the bottom of a ditch being dug may be controlled, said carrier having a removable inner bucket for carrying the load whereby a plurality of buckets may be alternated for permitting substantially continuous use of the carrier.

5. A device for handling bulk material comprising a boom having a longitudinal track and a downwardly curved track, a load carrier supported on said track, and automatic switch means for directing the carrier along the longitudinal track during movement toward the free end of the boom and along the downwardly curved track during inward movement of the carrier for picking up a load thereon whereby the device may be employed in digging a ditch, said boom being mounted for vertical swinging movement for raising and lowering the tracks and carrier whereby the elevation of the bottom of a ditch being dug may be controlled, said carrier having a removable inner bucket for carrying the load whereby a plurality of buckets may be alternated for permitting substantially continuous use of the carrier, said carrier being rollingly supported on said tracks, and cable means for pulling said carrier along said tracks.

6. An apparatus for handling bulk material such as earth comprising an elongated boom, means supporting the boom for swinging movement in a vertical and horizontal plane, a longitudinal trackway disposed on said boom, said trackway including a downwardly curved portion underlying and communicating with a longitudinal portion, a carrier movably mounted on said trackway, and means for moving the carrier longitudinally of said trackway, said trackway including switch means permitting the carrier to move outwardly along the longitudinal portion and inwardy along the downwardly curved portion for scooping a load of material in the carrier, said carrier including rollers engaging the trackway for supporting the carrier, a removable bucket mounted therein whereby the loaded bucket may be removed and replaced by an empty bucket for permitting substantially continuous operation of the apparatus, said trackway including parallel channel-shaped members, said switch means including a portion of the bottom of the inner end of the longitudinal portion being pivotally mounted at its outer end and resting on a supporting ledge at its inner end, thereby communicating the inner end of the downwardly curved portion with the longitudinal portion of the trackway for permitting the carrier to move outwardly along the bottom of the longitudinal portion and permitting the carrier to move upwardly and inwardly from the inner end of the downwardly curved portion onto the inner end of the longitudinal portion, said lontudinal portion of the channel-shaped members having an opening in the bottom thereof adjacent the outer end, said openings interconnecting the longitudinal and downwardly curved portions of the trackway, an angulated plate pivotally mounted at the inner edge of the opening and having an outer end of a size to close the opening in the trackway to permit the carrier to move longitudinally outwardly beyond the opening, the inner end of said plate extending below the longitudinal portion of the trackway and forming a counterbalance for normally urging the free end of the plate upwardly whereby the upwardly extending free end of the plate will 10 direct the carrier downwardly along the downwardly curved portion when it moves inwardly from the outermost end of the longitudinal portion.

7. In a system for moving bulk material, a dragline having a bucket, means for positively guiding the movement of the bucket, means for removing the loaded bucket from the dragline "at the inner end of its travel, means for positioning an empty bucket on the dragline at the inner end of its travel, and means for conveying the loaded bucket to a remote point and dumping the same while the empty bucket is being refilled by the dragline and subsequently returning the emptied bucket to a position for engagement with the inner end of the dragline after the filled bucket has been removed therefrom, thereby providing a substantially continuous operation.

8. An apparatus for handling bulk material comprising an elongated boom mounted for swinging movement in a vertical and horizontal plane, a trackway disposed longitudinally on said boom, a carrier movably supported directly on said trackway, said trackway including a longitudinal portion and a downwardly curved portion in communication with each other, the longitudinal portion of the trackway extending inwardly from the inner end of the downwardly curved portion of the trackway whereby the load on the carrier is removed while the carrier is disposed on the longitudinal portion inwardly of the downwardly curved portion with the carrier picking up the load during movement along the downwardly curved portion.

References Cited in the file of this patent UNITED STATES PATENTS 754,480 Moran Mar. 15, 1904 950,631 Bunnell Mar. 1, 1910 1,640,124 King Aug. 23, 1927 

